QRS fragmentation in children with suspected myocarditis: a possible additional diagnostic sign

Baseline and Follow-Up Cardiac Magnetic Resonance Imaging Findings in Children with Acute Myocarditis and Factors Associated with Late Gadolinium Enhancement

Objectives: Cardiac magnetic resonance (CMR) plays a central role in the diagnosis and follow-up of acute myocarditis (AM). In this study, we aimed to evaluate baseline and follow-up CMR findings and associated factors in children with AM. Methods: A retrospective analysis of CMR in pediatric patients with clinical presentations suggestive of myocarditis was performed. Patients' demographic characteristics, clinical data, and diagnostic test results, as well as CMR imaging results, were evaluated. Results: All 28 pediatric patients with acute myocarditis included in this study had late gadolinium enhancement (LGE) on initial CMR imaging. Additionally, 14 (50%) patients had increased extracellular volume (ECV), 4 (50%) patients had focal high-intensity areas on T2 STIR images, 15 (53.6%) patients had increased T1 relaxation time, and 17 (60.7%) patients had increased T2 relaxation time. At a median follow-up CMR of 6 months, 24 (85.7%) patients had LGE, 5 (17.9%) patients had increased ECV, and 7 (25%) patients had increased T1 relaxation time, while other parameters showed complete recovery. Baseline troponin and CRP levels, T1 relaxation time, T2 relaxation time, and increased ECV were found to be factors associated with the resolution of LGE. Conclusions: Baseline troponin and CRP levels, as well as T1 relaxation time, T2 relaxation time, and increased ECV, were effective parameters that seemed to predict the resolution of LGE. Larger and multicenter experiences would confirm these hypotheses.

The impact of fragmented QRS on clinical findings and outcomes in children with dilated cardiomyopathy with or without left ventricular non-compaction

OBJECTIVE

The aim of this study is to investigate the frequency of fragmented QRS and its associations with clinical findings and prognosis in children diagnosed with dilated cardiomyopathy with or without left ventricular non-compaction.

METHODS

This retrospective study was conducted between 2010 and 2020. Patients with dilated cardiomyopathy were classified into two groups according to the presence of left ventricular non-compaction: Dilated cardiomyopathy with left ventricular non-compaction and dilated cardiomyopathy without left ventricular non-compaction. Patients were also divided into two groups according to the presence of fragmented QRS (fragmented QRS group and non-fragmented QRS group).

RESULTS

Twenty-three of 44 patients (52.3%) were male. Among left ventricular non-compaction patients, the fragmented QRS group had more complex ventricular arrhythmias (p = 0.003). Patients with fragmented QRS had a significantly higher rate of major adverse cardiac events and/or cardiac death in both cardiomyopathy groups (p = 0.003 and p = 0.005). However, the rate of major adverse cardiac events and/or cardiac death was similar between dilated cardiomyopathy patients with and without left ventricular non-compaction. Multivariate logistic regression analysis showed that the presence of fragmented QRS strongly predicts major adverse cardiac events and/or cardiac death (odds ratio, 31.186; 95% confidence interval, 2.347-414.307). Although the survival rates between cardiomyopathy groups were similar, patients with fragmented QRS had a markedly lower survival rate during the follow-up period, as mean of 15 months (p = 0.001).

CONCLUSION

Our study showed that the presence of fragmented QRS may be an important ECG sign predicting an major adverse cardiac event and/or cardiac death in patients with dilated cardiomyopathy. We believe that recognising fragmented QRS could be valuable in forecasting patient prognosis and identifying high-risk patients who require additional support.

Early Diagnosis of Acute Myocarditis in the ED: Proposal of a New ECG-Based Protocol

The diagnosis of acute myocarditis (AM) is based on a multi-parametric assessment including clinical presentation, ECG, imaging and biomarkers. Fragmented QRS (fQRS) might be an additional diagnostic sign in patients with proven AM. The main objective of this study was to assess the diagnostic yield of fQRS in patients with suspected AM presenting to the emergency department (ED). Patients admitted between January 2016 and March 2021 with a proven diagnosis of AM, according to clinical, cardiac magnetic resonance (CMR) and/or histologic criteria, were included in the analysis. In total, 51 patients were analyzed (41 men, 78%), with a median age of 36 (29–45) years. Thirty-three (65%) patients had prodromal flu-like symptoms. Patients presented to the ED mostly complaining of chest pain (68%) and palpitations (21%). Seven (14%) patients experienced cardiac arrest, one of whom died. At presentation, 40 patients (78%) displayed fQRS, and 10 (20%) presented ventricular arrhythmias. All the surviving patients underwent CMR and displayed late gadolinium enhancement (LGE). ECG leads showed that fQRS matched the LGE distribution in 38 patients (95%). The presence of fQRS is a simple clinical bedside tool to support the initial suspect of AM in the emergency department and to guide the most appropriate clinical workup.

Evolution of acute myocarditis in a pediatric population: An MRI based study

BACKGROUND

Cardiac Magnetic Resonance (CMR) data regarding myocarditis presentation and disease course is still lacking in pediatric patients. We evaluate baseline CMR and evolution of functional and tissue abnormalities in children with acute myocarditis.

METHODS

CMR was performed in 125 patients with clinical diagnosis of acute myocarditis. Clinical follow-up was performed for a median of 498 (214-923) days.

RESULTS

LVEF was depressed (<55%) in 56 cases (45%) upon baseline CMR. LGE was found in 93 patients (77%) of cases. LGE was exclusively subepicardial in 29 patients (23%), while other LGE patterns (midwall/mixed) were present in 64 (51%). CMR was repeated in 92 (74%) patients. 67% presented recover of function at a median of 170 (70-746) days after onset of symptoms. Midwall/mixed LGE pattern had a statistically significant correlation with absent recover of function (OR 0.20 p 0.036). Thirteen patients (16%) had recovery from LV dysfunction but with persistence of LGE. Sub-epicardial pattern of LGE (OR 3.33, 95% CI 1.08-10.2, p = 0.036) and the presence of fever at admission (OR 4.67, 95% CI 1.16-18.7, p = 0.03) were associated with a significantly higher likelihood of complete normalization while midwall/mixed LGE pattern was associated with non-recovery.

CONCLUSIONS

In pediatric myocarditis, midwall/mixed LGE pattern is associated with absent recover of function. Patients with recover of function may still have persistence of LGE, while a complete recovery from functional and tissue abnormalities is found only in a third of patients. Midwall/mixed pattern of LGE at first MRI was associated to worse outcome.